National Instruments AT-MIO-16X - Manual (Page 90)

Chapter 3 Theory of Operation
AT-MIO-16X User Manual 3-24 © National Instruments Corporation
In the pulsed waveform application, Counter 1 of the Am9513A is
programmed to count the number of retransmit signals, before
terminating the sequence. At this point, Counter 2 serves as an interval
timer and then restarting the sequence. This process proceeds ad
infinitum until the timer trigger is removed or disabled, or the
CYCLICSTOP bit is set.
Digital I/O Circuitry
The AT-MIO-16X has eight digital I/O lines. These eight digital I/O
lines are divided into two ports of four lines each and are located at pins
ADIO<3..0> and BDIO<3..0> on the I/O connector. Figure 3-16 shows
a block diagram of the digital I/O circuitry.
Figure 3-16. Digital I/O Circuitry Block Diagram
I/O Connector
A
Digital
Input
Register
B
DOUT0
Digital
Output
Register
DOUT1
Digital
Output
Register
EXT STROBE WR*
EXTSTROBE*
/
4
/
4
/
4
/
4
DO REG WR
DOUT0 ENABLE
/
4
DATA <3..0>
DATA <7..4>
/
4
DOUT1 ENABLE
DIREG RD
DATA <7..0>
/
8
BDIO <3..0>
ADIO <3..0>
PC I/O Channel